Migliano P, Kabiri LS, Cross M, Butcher A, Fruge A, Brewer W, Ortiz A. Validation of Cardiorespiratory Fitness Measurements in Adolescents. Journal of Functional Morphology and Kinesiology. 2019 July;4(3):44.
Abstract: Cardiorespiratory fitness (CRF) is an important indicator of adolescent cardiovascular well-being and future cardiometabolic health but not always feasible to measure. The purpose of this study was to estimate the concurrent validity of the non-exercise test (NET) for adolescents against the Progressive Aerobic Capacity Endurance Run (PACER®) and direct measures of VO2max as well as to examine the concurrent validity of the PACER® with a portable metabolic system (K4b2™). Forty-six adolescents (12–17 years) completed the NET prior to performing the PACER® while wearing the K4b2™. The obtained VO2max values were compared using linear regression, intra-class correlation (ICC), and Bland–Altman plots, and α was set at 0.05. The VO2max acquired directly from the K4b2™ was significantly correlated to the VO2max indirectly estimated from the NET (r = 0.73, p < 0.001, r2 = 0.53, ICC = 0.67). PACER® results were significantly related to the VO2max estimates from the NET (r = 0.81, p < 0.001, r2 = 0.65, ICC = 0.72). Direct measures from the K4b2™ were significantly correlated to the VO2max estimates from the PACER® (r = 0.87, p < 0.001, r2 = 0.75, ICC = 0.93). The NET is a valid measure of CRF in adolescents and can be used when an exercise test is not feasible.
Kabiri LS, Butcher A, Brewer W, Ortiz A. Youth physical health and years in American homeschools: are they related?. Health Promotion International. 2019. ePub ahead of print.
Abstract: Homeschooling is a growing trend in the USA and abroad with both reported consequences and benefits to youth physical health. The purpose of this study was to examine whether changes in youth physical health could be related to the number of years a student spends in homeschool. Body composition (body mass index and body fat), muscular fitness (lower extremity, abdominal and upper extremity) and cardiorespiratory fitness (Progressive Aerobic Capacity Endurance Run) were assessed in 211 youth ages 5–17. Data analysis showed weak or non-significant relationships between years in homeschool and all aspects of youth physical health. Time spent in homeschool is weakly or not at all related to multiple aspects of youth physical health. Parents and policy makers should not be concerned with detrimental physical health effects of homeschooling on youth.
Kabiri LS, Rodriguez AX, Perkins-Ball AM, Diep CS. Organized Sports and Physical Activities as Sole Influencers of Fitness: The Homeschool Population. Journal of Functional Morphology and Kinesiology. 2019 Mar;4(1):13.
Abstract: Homeschool children may rely solely on organized sports and physical activities to achieve recommended levels of physical activity and fitness. The purpose of this study was to investigate differences in fitness levels between homeschool children who did, and did not, participate in organized sports or physical activities, and then examine relationships between hours per week in sports or physical activities and cardiorespiratory fitness as measured by portions of the FitnessGram® test battery. Organized sports/physical activity participation information was gathered on 100 children ages 10–17 years who completed tests of upper, abdominal, and cardiorespiratory fitness. The current investigation revealed that participation alone was not associated with higher levels of physical fitness as assessed by the 90° push-up test or curl-up test nor was time in participation related to cardiorespiratory fitness as assessed by the Progressive Aerobic Capacity Endurance Run (PACER). These activities alone may be insufficient for meeting physical activity recommendations and improving physical fitness. Therefore, children and adolescents educated at home may need additional opportunities to participate in unstructured daily physical activity.
Butcher A, Kabiri LS, Brewer W, Ortiz A. Criterion Validity and Sensitivity to Change of a Pediatric Bioelectrical Impedance Analysis Scale in Adolescents. Childhood Obesity. 2018 Oct 23.
Abstract: BMI measures are often used to infer body composition. Bioelectrical impedance analysis (BIA) is a more accurate way to estimate percent body fat (%BF), particularly when screening children who may be overweight. The aim of this study was to determine the validity, sensitivity to change, and diagnostic value of a BIA scale designed specifically for adolescents. One hundred twelve adolescents had their body fat assessed using both BIA and dual-energy X-ray absorptiometry (DEXA). Mean difference and limits of agreement (LoA) were calculated for criterion validity. Intraclass correlation coefficients (ICCs) were calculated for sensitivity to change. Sensitivity/specificity for each classification was also assessed. Data from 46 returning adolescents (6–8 months later) were then used to assess sensitivity to change of BIA compared with DEXA. ICC for absolute agreement (range) comparing BIA and DEXA was 0.78 (0.48–0.88). The mean difference between the BIA %BF reading and DEXA was −4.05% (LoA = [4.80%, −12.90%]). Sensitivity and specificity values for the underfat, healthy, overfat, and obese classifications were 0.0/0.89, 0.79/0.46, 0.28/0.92, and 0.5/1.00, respectively. ICC for absolute agreement over time between the BIA %BF and the DEXA %BF was 0.71 (0.242–0.866). The Tanita BF-689 demonstrated poor–good agreement with DEXA when measuring %BF, poor–moderate agreement when measuring change in %BF over time, high sensitivity for classification into the healthy category and high specificity for classification into the underfat/overfat/obese categories. Compared to DEXA, the BF-689 is accurate, accessible, and efficient in classifying adolescents based on %BF.
Kabiri LS, Mitchell K, Brewer W, Ortiz A. How Healthy Is Homeschool? An Analysis of Body Composition and Cardiovascular Disease Risk. Journal of School Health. 2018 Feb;88(2):132-8.
Abstract: Public school children regularly participate in school‐based physical activity, physical education, and fitness testing. However, almost 2 million American children are homeschooled. The purpose of this research was to assess the body composition of elementary school‐aged homeschool children and their corresponding cardiovascular disease (CVD) risk. This research explored the body composition and CVD risk of 145 homeschool children aged 5–11 years using body mass index (BMI), percent body fat, and waist circumference. Chi‐square and Mann‐Whitney U tests examined differences in CVD risk within the homeschool population. Overall, homeschool children had average BMI z‐scores (SD [range]) with a mean of −0.11 (0.97 [−3.47 to 2.53]). Unhealthy classifications were seen in 11.2% of the sample by BMI, 19.6% by percent body fat, and 49.7% by waist circumference. Statistical analysis revealed no difference in CVD risk between sexes (χ2(1) = 0.062, p = .804) or ethnicities (χ2(1) = 0.927, p = .336) but increased prevalence in children aged 5–9 years (U = 1427, z = −4.559, p < .001). Almost half of elementary school‐aged homeschool children showed increased risk for CVD and need regular assessment of central adiposity.
Kabiri LS, Mitchell K, Brewer W, Ortiz A. Motor Skill Proficiency Among Homeschooled Children. Journal of Motor Learning and Development. 2017 Dec;5(2):336-45.
Abstract: Almost 2 million American children are homeschooled but no information is currently available regarding motor skill proficiency within this population. The purpose of this research was to describe motor skill proficiency among homeschooled children and assess differences in homeschooled subgroups. This cross-sectional study screened 73 homeschooled children aged 5–8 years for overall motor skill proficiency using the Bruininks-Oseretsky Test of Motor Proficiency, Second Edition, Short Form (BOT-2 SF). Independent t tests examined differences in motor skill proficiency within the homeschooled population. Mann-Whitney U tests examined differences in motor skill proficiency classification within significantly different subgroups. Homeschooled children demonstrated average motor proficiency. Significantly different motor proficiency was seen among homeschooled children participating in 3 or more hours of organized sports per week, t(71) = 2.805, p = .006, 95% CI = 1.77, 10.49, and whose primary caregiver was employed versus unemployed, t(71) = –3.875, p < .001, 95% CI = –13.29, –4.26. Mann-Whitney U tests revealed significantly different motor skill proficiency classification in these same subgroups. Overall, homeschooling showed no detrimental effect on motor skill proficiency. Participation in 3 or more hours of organized sports per week or having an unemployed primary caregiver may improve motor skill proficiency among this population.
Hernandez DC, Reesor L, Kabiri LS. Maternal concerns and perceptions of elementary school‐age children's weight status. Journal for Specialists in Pediatric Nursing. 2017 Oct;22(4):e12191.
Abstract: The purpose of this study was to identify characteristics associated with maternal concerns for her child becoming overweight, and how these concerns are related to her perceptions of her child's weight. A school‐based sample of 55 children and their mothers from Houston, Texas, participated in a cross‐sectional survey. Mothers reported on their concerns and perceptions regarding their child's weight. Child and mother height and weight were directly assessed to calculate body mass index (BMI). Covariate‐adjusted logistic regression models were conducted. Over one‐third of mothers misperceived their child's weight status [9% (n = 5) overestimated; 27% (n = 15) underestimated]. Mothers of sons were less accurate compared with mothers of daughters. For every one unit increase in maternal BMI, mothers had 13% higher odds of being concerned of their child becoming overweight. Concerned mothers had 82% lower odds of underestimating their child's weight. In order for school‐based childhood obesity prevention and intervention programs to be successful, parents must accurately perceive their elementary school‐age child's weight status. School nurses can be vital to these efforts through proper training and resources. Nurses can use the “School Nurse Childhood Obesity Toolkit” and motivational interviewing techniques to address parental concerns and perceptions prior to teaching behavior modification strategies to children/families.
Kabiri LS, Mitchell K, Brewer W, Ortiz A. Muscular and cardiorespiratory fitness in homeschool versus public school children. Pediatric Exercise Science. 2017 Aug;29(3):371-6.
Abstract: The growth and unregulated structure of homeschooling creates an unknown population in regard to muscular and cardiorespiratory fitness. The purpose of this research was to compare muscular and cardiorespiratory fitness between elementary school aged homeschool and public school children. Homeschool children ages 8–11 years old (n = 75) completed the curl-up, 90° push-up, and Progressive Aerobic Capacity Endurance Run (PACER) portions of the FitnessGram to assess abdominal and upper body strength and endurance as well as cardiorespiratory fitness. Comparisons to public school children (n = 75) were made using t tests and chi-square tests. Homeschool children showed significantly lower abdominal (t(148) = -11.441, p < .001; χ2 (1) = 35.503, p < .001) and upper body (t(148) = -3.610, p < .001; χ2 (1) = 4.881, p = .027) strength and endurance. There were no significant differences in cardiorespiratory fitness by total PACER laps (t(108) = 0.879, p = .381) or estimated VO2max (t(70) = 1.187, p = .239; χ2 (1) = 1.444, p = .486). Homeschool children showed significantly lower levels of both abdominal and upper body muscular fitness compared with their age and gender matched public school peers but no difference in cardiorespiratory fitness.
Kabiri LS, Hernandez DC, Mitchell K. Reliability, validity, and diagnostic value of a pediatric bioelectrical impedance analysis scale. Childhood Obesity. 2015 Oct 1;11(5):650-5.
Abstract: Accurate body composition assessment is critical to identify children who are overfat or obese. Unlike BMI measures, bioelectrical impedance analysis (BIA) differentiates between lean and fat mass. However, bioelectrical impedance analysis has historically had questionable reliability and validity in children. The aim of this study was to determine the reliability, validity, and diagnostic value of a portable BIA scale (Tanita BF-689; Tanita Corporation, Tokyo, Japan) designed specifically for use within the pediatric population. Fifty-five children (males = 26; females = 29) had percent body fat (%BF) assessed twice using BIA and once using dual-energy X-ray absorptiometry (DEXA). Intraclass correlation coefficients (ICCs) were calculated for reliability. Mean difference and limits of agreement were calculated for convergent validity. Sensitivity/specificity for healthy, overfat, and obese classification were assessed. Test-retest ICC was 0.999 (0.999, 0.999). The ICC comparing BIA and DEXA for %BF was 0.788 (−0.167, 0.942). Mean difference between BIA and DEXA was −6.75% (limits of agreement = −0.04%; −13.46%). No gender or proportional bias was observed. Sensitivity/specificity for healthy, overfat, and obese classification were 0.67/0.65, 0.22/0.78, and 0.43/1.0, respectively. The Tanita BF-689 demonstrates excellent test-retest reliability, moderately strong absolute agreement with DEXA, and high specificity for overfat and obese classification. Compared to DEXA, the BF-689 is an accurate, portable, and efficient means of assessing %BF in elementary school children.
Kabiri L, Tapley H, Tapley S. Evaluation and conservative treatment for Osgood-Schlatter disease: A critical review of the literature. International Journal of Therapy and Rehabilitation. 2014 Feb;21(2):91-6.
Abstract: Osgood-Schlatter disease (OSD) is a tibial tubercle traction apophysitis resulting from repetitive strain on the patellar tendon insertion. OSD can lead to significant functional limitations and disability that can persist into adulthood. The authors of this review systematically searched PubMed, CINAHL, TWUniversal, and The Cochrane Library for articles dated from January 1980 to December 2013 that related to the evaluation and conservative treatment of Osgood-Schlatter disease. Search phrases included ‘Osgood-Schlatter disease AND diagnosis’ and ‘Osgood-Schlatter disease AND treatment’. Articles were assessed for evidence strength based upon modified criteria from the evidence-based medicine pyramid and the diagnosis and treatment sections of the Oxford Centre for Evidence-Based Medicine 2011 Levels of Evidence Table.There is a wealth of evidence to support a clinical diagnosis of Osgood-Schlatter disease. There is also fair evidence to employ functional outcome measures during evaluation. Evidence concerning conservative treatments for Osgood-Schlatter disease ranges from poor to strong based upon the intervention. While strong evidence for clinical diagnosis is supported by the literature, further research is required to establish definitive functional outcome measures and effective interventions in the management of Osgood-Schlatter disease.